Fighting 🧯 Fatigue 😰

What is really important about your power abilities? Absolute, gross power numbers show us what you are capable of but are they the most important feature of your power?

The 20 minute FTP test is a great case in point. Many riders approach this test in a nice rested state, warm up, and then hammer out a 20 minute effort. FTP is then set at 95% of the 20 minute average power, with all training zones set from this level. In almost all cases this results in an FTP set too high due to the anaerobic contribution of  a singular 20 minute effort.

I would wager a lot of money that most people who set their FTP like this could not hold that average power for more than 30 minutes at best.

So what happens?

You work at an effort level that causes muscular fatigue and a reduction in performance.

Most failure in races and longer endurance events has nothing to do with absolute power – you just run out of energy and fatigue too quickly.

A lot of the work we do with our riders is aimed at improving the point at which fatigue sets in and performance drops off.

We look to improve FATIGUE RESISTANCE

Now this should be specific to the rider and also specific to the demands of their race or event.

For example a racer would be very interested in how quickly they fatigue in a sprint. This would inform both training and race tactics. Using WKO4 we can create a fatigue profile to show us this performance. As you can see below this rider has very stable power out to 12 seconds but then power drops away by 25% by 20 seconds. In terms of race tactics this rider would not want to be launching any long range sprints. In terms of training we would look both to improve absolute power but also to INCREASE THE TIME THAT POWER CAN BE SUSTAINED FOR.

For Gran Fondo and endurance riders it is the longer time frames that would be interesting.

How much does your power fall from say 30 minutes to 60 minutes? From 60 – 90minutes and so on…….

If you are training for an alpine Gran Fondo then you know that you need to be able to lay down sustained efforts for 60 and sometimes 90-120 minutes for some of the epic high mountain climbs, and then do that maybe 3 or 4 times or more…..


So we prescribe very unfashionable long intervals for this type of event. Long tempo efforts, building to 90 minutes+ in a single session is a great way to prepare for the rigours of mountain riding and gets the body used to sustained efforts. After a few weeks of consistent tempo efforts the body adapts and muscular fatigue lessens and stamina increases.

You can see in the chart and table below that this rider has an FTP of 287w, a 2hr best of 220w and a 4hr best of 170w. This is illustrating his current fatigue resistance over long time periods. Improving FTP is good, but improving his 2hr to 4hr drop in power would be much more effective at improving his finishing times in long endurance events.

Tempo training will improve Gran Fondo and Sportive finishing times significantly by improving resistance to muscular fatigue, and is not too demanding physiologically so these sessions can be repeated frequently. Threshold training has a part to play but it is too demanding to be repeated day after day, week after week, throughout the whole season and may not specifically target the ability you are aiming to improve.

Focusing on absolute power numbers is an important, but not sufficient way to assess strengths and weaknesses. Increasing absolute power for a discrete time period is cool but increasing power for longer durations of time can be much more beneficial in improving results.

To find out more please get in touch

Have a great week riding

Rob Wakefield – Propello Founder and Head Coach